The PLATO system
was an early, influential system in the development of online communication.
The PLATO system was originally created in the early 1960's at the University
of Illinois at Urbana by Don Bitzer, an electrical engineering professor interested
in using computers for teaching, who together with several colleagues founded
the Computer-based Education Research Laboratory (CERL).

The original PLATO
system was comprised of custom developed hardware and software, and one
of the first time-sharing systems. In 1972, the software was ported to a
more powerful mainframe platform with support for hundreds of simultaneous
users.
Today, a working copy of PLATO can be found on the Internet running at Cyber1.org.

Notes. The PLATO Notes application was originally written by David Woolley to extend an existing program for reporting system bugs. It occurred to him as he developed the application that a single response from the system staff to each reported bug (note) was too restrictive, so he added a feature to allow up to 63 responses to each note, thereby enabling an ongoing conversation. As the power of this idea became apparent, Woolley extended the system to enable conversations on general topics in addition to reporting system bugs. The updated Notes application was deployed 7 August, 1973, and quickly became one of the most popular features on the PLATO system.

Talkomatic. In the fall of 1973, Doug Brown wrote a basic program called Talkomatic to support chat among users on PLATO. The screen was divided into several horizontal windows, with a separate window for each participant, and enabled each user to type at the same time. Talkomatic transmitted characters as they were entered, so that each user could see the messages appear as they being typed, which greatly added to the real-time feel of the application.

Talkomatic was soon extended to support multiple channels, each with up to five participants (limited by the size of the screen) and any number of non-participating monitors, and quickly became one of the most popular applications on the PLATO system. A similar two-person communication program modeled on Talkomatic was also developed called term-talk, which enabled any two people to communicate without exiting their current program - kind of an early instant massaging system.

Personal Notes. Kim Mast extended Notes to implement a personal mail system called Personal Notes, released in August of 1974. Mast and Woolley worked together to integrate all of PLATO's communication features into a single application, combining Notes, Personal Notes, and term-talk.

Group Notes. As Notes became more popular, it became apparent that it needed generalization to scale up in size. After a fair amount of research and experimentation, Woolley released the application Group Notes in January, 1976. Group Notes supported an unlimited number of notes files, both public and project related, greatly extending its applicability, and use of the system skyrocketed. Before long public forums were established for discussion of subjects such as movies, music, religion, and science fiction, and private notes files were set up for communication among groups working on individual projects. One of the most popular forums was a set of surrealistic stories posted by a student at the University of Delaware named David J. Graper, which became collected as Grapenotes.

Starting in 1975, Control Data Corporation began to turn the PLATO system into a commercial product, and by 1985 more than a hundred such systems were operating at commercial, university, and government sites around the world. Several of the sites were linked together by dedicated lines, so in 1978 the Notes application was extended again to enable inter-site communication, so that notes files could be linked across systems to appear as one integrated forum.

Interestingly, the extended PLATO community showed much the same evolution
as other online communities such as the Usenet newsgroups and Mailing lists,
with development of the full spectrum of idiosyncratic human behavior, including
flaming sessions,
people impersonating others, heated political discussions, and the development
of online relationships that later blossomed into off-line friendships, including
many marriages.

Denouement. As the Control Data Corporation ran into financial trouble in the late 1980's, and microcomputers became a more cost-effective platform than mainframes, many PLATO systems were closed down. The PLATO name was sold to a Minneapolis-based company called PLATO Learning, Inc. Control Data's PLATO system was renamed CYBIS, and continued to be supported at several university and government sites still running the original PLATO Notes software. The University of Illinois PLATO system was renamed NovaNET, and transferred to a private company called NovaNET Learning, Inc., of Tucson, Arizona.

The CERL PLATO system, only one of the sites deployed around the world, logged 10 million hours of use between September, 1978 and May, 1985, the period for which the most complete statistics are available. About one third of those hours were spent using the Notes application. About 3.3 million messages were posted in about 2000 notes files.

Many subsequently developed software systems were influenced by PLATO, including the very successful commercial product Lotus Notes, developed by Ray Ozzie, Tim Halvorsen, and Len Kawell, all of whom had worked at CERL in the late 1970's.